JP2005348512A - Dynamo-electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamo-electric machine which can be cooled without being provided with a separate cooler even in case that the heating density is high, by making its physical constitution small. <P>SOLUTION: The dynamo-electric machine 1 is equipped with two stator cores 10 where coils 13 are wound concentratedly on teeth parts 12 which are made in plural numbers to project inward from a circular yoke 11, and a rotor 20 which is arranged to pass inside the two stators 10 and rotates to the stator core 10 by the magnetic fields generated by the teeth parts 12. Then, the rotor 20 is provided with a radial fan 22 for cooling the coil end part 13a of the coil 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotating electrical machine, and more particularly to a rotating electrical machine for wind power generation.

  In recent years, the amount of power generation systems introduced by wind power generation has increased dramatically. Along with this, there is an increasing demand for an increase in the capacity of the power generation system, that is, an increase in the amount of power generated by a generator (rotary electric machine). In order to achieve such a large capacity, the rotating torque applied to the generator shaft is increased by enlarging the blades rotating by the force of the wind, so that the increased rotational torque is increased by the generator. There was a need to efficiently convert to electrical energy.

  By the way, if the conversion from the large rotational torque to the large electric energy is performed by one generator, even if the efficiency is set as high as 99% and the loss is suppressed to about 1%, it is inputted. Since the rotational torque itself is increased, the absolute value of the loss (heat generation amount) is larger than that of a conventional small-capacity generator. Therefore, if the size of the generator is reduced, its heat generation density increases, so it is necessary to provide a separate cooling device, and in order to make the heat generation density comparable to that of a conventional small capacity generator, When the physique was enlarged, there was a problem that the weight increased. In particular, when the weight increases, the generator is installed at the top of the tower about 100m above the ground due to the characteristics of wind power generation, so it is necessary to lift heavy objects to a height of 100m, which increases construction costs. Was.

  Conventionally, a technique for connecting a plurality of small-capacity generators arranged in the axial direction is known as an improvement measure for the above problems (see Patent Documents 1 and 2). According to this technique, it is possible to suppress an increase in weight without increasing the heat generation density of the generator.

JP 2001-186740 A JP-A-10-318120

  However, the conventional technique has a problem of increasing the size in the axial direction because a plurality of generators are connected in the axial direction.

  Accordingly, an object of the present invention is to provide a rotating electrical machine that can be cooled without providing a separate cooling device even when the heat generation density is increased by reducing the size of the rotating electrical machine. To do.

  The present invention for solving the above-described problems includes a plurality of stator cores in which coils are concentratedly wound around a plurality of teeth portions formed so as to protrude inward from an annular yoke portion, and pass through the plurality of stator cores. A rotating electrical machine including a rotor that rotates with respect to the stator core by a magnetic field generated from the teeth portion, and for cooling the coil end portion of the coil to the rotor. A fan is provided. According to the present invention, the coil end portion of the coil is cooled by the fan that rotates together with the rotor.

  According to the present invention, since the coil end portion of the coil is cooled by the fan that rotates together with the rotor, even if the heat generation density is increased by reducing the size of the rotating electrical machine, The rotating electrical machine can be cooled without providing a cooling device.

[First Embodiment]
Next, a first embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a perspective view showing the rotating electrical machine according to the first embodiment, FIG. 2 is a side view showing the state of the rotating electrical machine viewed from the side, and FIG. FIG.

  As shown in FIG. 1 and FIG. 2, the rotating electrical machine 1 is mainly configured by two stator cores 10 and a rotor 20 disposed so as to pass through these stator cores 10. In the present embodiment, an 8-pole magnetic pole is electrically formed by appropriately applying a current to a coil 13 (described later) housed in 12 slots (grooves) of the stator core 10. Although a 12-slot rotary electric machine will be described, the present invention is not limited to this, and any rotary electric machine may be used.

  The stator core 10 is mainly composed of an annular yoke portion 11 and twelve (plural) teeth portions 12 formed so as to protrude inward from the inner peripheral surface of the yoke portion 11. . A coil 13 is intensively wound around each tooth portion 12, and a predetermined current (U-phase, V-phase, W-phase AC current) is appropriately passed through each of the concentrated coils 13. Thus, a predetermined magnetic field (eight magnetic field; four N poles and four S poles) is generated from each tooth portion 12.

  Specifically, if the first coil 13A, the second coil 13B,..., And the twelfth coil 13M (see FIG. 3) are sequentially called from the coil 13 positioned at the top in the clockwise direction, A U-phase alternating current is supplied to the first coil 13A, the fourth coil 13D, the seventh coil 13G, and the tenth coil 13J, and the second coil 13B, the fifth coil 13E, the eighth coil 13H, and the eleventh coil 13L. A V-phase alternating current is supplied, and a W-phase alternating current is supplied to the third coil 13C, the sixth coil 13F, the ninth coil 13I, and the twelfth coil 13M. That is, an alternating current of U phase, V phase, W phase, U phase, V phase, W phase, U phase,... Is supplied in order from the uppermost first coil 13A in the clockwise direction. It has become. In the following description, for convenience, each tooth portion 12 corresponding to each of the coils 13A to 13M is also referred to as a first tooth portion 12A, a second tooth portion 12B, ..., and a twelfth tooth portion 12M. .

  In addition, as shown in FIG. 3, the two stator cores 10 each have one stator core 10 (hereinafter also referred to as “first stator 10 </ b> A”) and the other stator core 10 (hereinafter, “ The second stator 10B ”is also arranged so as to be shifted by a predetermined phase difference (phase angle α). Here, the phase angle α is, for example, when the second stator 10B is rotated by a predetermined amount from the state where the centers of the first stator 10A and the second stator 10B and the teeth portions 12 are combined. The angle which each teeth part 12 (1st teeth part 12A in the figure) makes is said.

  That is, the auxiliary line 31 that passes through the center of the first teeth portion 12A in the first stator 10A and passes through the center of the first stator 10A and the center portion of the first teeth portion 12A in the second stator 10B. The angle formed by the auxiliary line 32 that passes through and passes through the center of the second stator 10B is referred to as a phase angle α. In addition, although the auxiliary lines 31 and 32 do not actually intersect, as shown in FIG. 3, by projecting the auxiliary lines 31 and 32 onto a plane orthogonal to the axial direction of each stator core 10, The phase angle α is derived by intersecting the auxiliary lines 31 and 32.

The phase angle α in the present embodiment is 7.5 ° (degrees) as an actual mechanical angle and 30 ° as an electrical angle. The electrical angle refers to what expresses the space between the poles of the same name as 360 °, and is specifically expressed by the following formula.
Electrical angle (°) = Mechanical angle (°) × Number of poles ÷ 2
Here, the number of poles refers to the number of magnetic poles (N pole and S pole). In other words, the electrical angle (30 °) is calculated by substituting the mechanical angle (7.5 °) and the number of poles (8 poles) into this equation.

  The relationship between the electrical angle and the cogging torque (change in torque based on the magnetic attractive force generated between the stator core 10 and the rotor 20 with respect to the rotation angle, so-called torque unevenness) is as shown in FIG. It has become a relationship. In the drawings to be referred to, FIG. 4 is a graph in which the horizontal axis represents the electrical angle and the vertical axis represents the cogging torque, and is normalized with the cogging torque when the electrical angle is 0 ° being 100%.

  As shown in FIG. 4, the relationship between the electrical angle and the cogging torque is such that the cogging torque is reduced as the electrical angle approaches 30 °. When the electrical angle reaches 30 °, the cogging torque becomes 0%, so that the cogging torque can be completely eliminated. Note that the electrical angle is not limited to 30 °, and may be any number. For example, the electrical angle is preferably set within a range of 10 ° to 30 °.

  As shown in FIGS. 1 and 2, the rotor 20 is rotated with respect to the stator core 10 by a magnetic field generated from each tooth portion 12, and both ends thereof are rotatably supported by bearings (not shown). Has been. The rotor 20 includes two magnet portions 21, which are cylindrical permanent magnets having eight magnetic poles (four N poles and four S poles) on the outer peripheral surface thereof, and between these magnet portions 21. And a radial fan 22 provided in the main body.

  The two magnet parts 21 are disposed at the same phase angle. And these magnet parts 21 are arrange | positioned so that it may overlap with the 1st stator 10A and the 2nd stator 10B, respectively in the side view as shown in FIG. 2 (viewing from the radial direction of the rotor 20). Yes. That is, the teeth portion 12 of the first stator 10A and the second stator 10B is disposed around the magnet portion 21 so as to surround it.

  The radial fan 22 is a fan that sends air toward the radially outer side, and is provided so as to overlap the coil end portions 13a of the coils 13 of the first stator 10A and the second stator 10B in a side view. Here, the coil end portion 13a refers to a portion of the coil 13 that protrudes outward from the stator core 10, and particularly refers to a portion that generates heat when energized. Therefore, the portion on the opposite side not surrounded by the dotted line in FIG. 2 is also referred to as a coil end portion.

Next, the operation of the rotating electrical machine 1 will be described.
As shown in FIG. 1, each of the coils 13 is supplied with a U-phase, V-phase, and W-phase AC current as appropriate, or an external force (for example, rotational torque generated by a windmill) is applied to the rotor 20. When rotating, the radial fan 22 also rotates with the rotation of the rotor 20. When the radial fan 22 rotates in this way, wind is sent out radially outward from the radial fan 22, and the coil end portion 13a in the vicinity of the radial fan 22 is cooled as shown in FIG. Become.

According to the above, the following effects can be obtained in the first embodiment.
Since the coil end portion 13a is efficiently cooled by the radial fan 22 that rotates together with the rotor 20, even if the heat generation density is increased by reducing the size of the rotating electrical machine 1, it is separately cooled. The rotating electrical machine 1 can be cooled without providing a device.

  Since the phase angle α of the two stator cores 10 is set to be 30 ° in electrical angle, the influence of cogging torque can be completely eliminated.

[Second Embodiment]
The second embodiment of the present invention will be described below. Since this embodiment is obtained by changing a part of the rotating electrical machine 1 of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the drawings to be referred to, FIG. 5 is a side view showing a rotating electrical machine according to the second embodiment.

  As shown in FIG. 5, the rotary electric machine 2 is mainly composed of three stator cores 40, 10, 40 and a rotor 50 that passes through the stator cores 40, 10, 40. Here, the stator core 10 disposed in the middle has a structure substantially similar to that of the first embodiment.

  The two stator cores 40 are arranged so as to be shifted in the same direction by a predetermined phase difference (the aforementioned phase angle α) with respect to the middle stator core 10. Further, the two stator cores 40 are formed such that the stack thickness (the length in the central axis direction of the stator core 40) t is half of the stack thickness 2t of the stator core 10 in the middle. . That is, the thickness obtained by adding the laminated thickness t of the two stator cores 40 on the outer side is the laminated thickness 2t of the middle stator core 10.

  The rotor 50 is mainly configured by three magnet portions 21 having a structure substantially similar to that of the first embodiment, and two radial fans 22 disposed between the magnet portions 21. Each radial fan 22 has a coil end portion in side view so that the coil end portion 13a of the coil 13 wound around the two stator cores 40, 10 located on both sides of the radial fan 22 can be cooled. It arrange | positions so that the part 13a may overlap.

  Note that a predetermined thrust force is applied to the rotor 50 along the axial direction because the two outer stator cores 40 are shifted by a predetermined phase difference with respect to the middle stator core 10. Has been added. Specifically, this thrust force is applied by the outer stator cores 40 in the direction toward the middle stator core 10, and is applied in the outer directions by the middle stator core 10. Further, this thrust force is proportional to the laminated thickness of the stator cores 40 and 10.

  Therefore, from the stator core 40 on the left side of the figure, a thrust force proportional to the laminate thickness t works in the right direction, and from the middle stator core 10 to a laminate thickness t that is half of the laminate thickness 2t. Proportional thrust forces work in the left direction so that these thrust forces are countered. Similarly, from the stator core 10 in the middle, a thrust force proportional to the laminate thickness t, which is the other half of the laminate thickness 2t, works in the right direction, and from the stator core 40 on the right side of the figure, A thrust force proportional to the stacking thickness t works in the left direction, so that these thrust forces are canceled out.

According to the above, the following effects can be obtained in the second embodiment.
Since the two radial fans 22 are provided between the three stator cores 40, 10, 40, the coil end portions 13 a of the stator cores 40, 10 can be cooled well. In particular, with respect to the stator core 10 positioned on the inner side, the coil end portions 13a on both sides are cooled by the two radial fans 22, so that the coil 13 can be cooled more efficiently.

  Since the thickness of the stator core 10 in the middle is 2t, which is the sum of the thickness t of the two stator cores 40 on the outside, the thrust force generated from each stator core 40 can be canceled out. .

[Third Embodiment]
The third embodiment of the present invention will be described below. Since this embodiment is obtained by changing a part of the rotating electrical machine 1 of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the drawings to be referred to, FIG. 6 is a side view showing a rotating electrical machine according to the third embodiment.

  As shown in FIG. 6, the rotating electrical machine 3 is mainly composed of four stator cores 10 and a rotor 60 that passes through the stator cores 10.

  The stator core 10 has substantially the same structure as that of the first embodiment. The two outer stator cores 10 out of the four are disposed so as to be shifted in the same direction by a predetermined phase difference (the aforementioned phase angle α) with respect to the middle two stator cores 10. Yes. Incidentally, the two stator cores 10 in the middle have the same phase, and the two outer stator cores 10 have the same phase.

  The rotor 60 is mainly configured by four magnet portions 21 having substantially the same structure as that of the first embodiment, and three radial fans 22 disposed between the magnet portions 21. Each radial fan 22 has a coil end portion 13a in a side view so that the coil end portions 13a of the coil 13 wound around the two stator cores 10 located on both sides of the radial fan 22 can be cooled. Are arranged so as to overlap.

  A predetermined thrust force is applied to the rotor 60 in the axial direction in the same manner as described above, but the thrust force applied inwardly from the two stator cores 10 positioned on the outer side is the same. The thrust is applied by the thrust force applied outward from the two inner stator cores 10 having the same thickness as the stator core 10.

According to the above, the following effects can be obtained in the third embodiment.
Since the three radial fans 22 are provided between the four stator cores 10, the coil end portions 13 a of the stator cores 10 can be cooled well. In particular, with respect to the stator core 10 positioned on the inner side, the coil end portions 13a on both sides are cooled by the two radial fans 22, so that the coil 13 can be cooled more efficiently.

As mentioned above, this invention is implemented in various forms, without being limited to the said embodiment.
In the present embodiment, the radial fan 22 is provided between the stator cores 10 and 40. However, the present invention is not limited to this, and the radial fan 22 may be provided anywhere. For example, the radial fan 22 may be provided at both ends of the rotor 20 in the first embodiment so as to overlap the coil end portion (one not surrounded by a dotted line) in a side view. According to this, since both the coil end portions 13a protruding on both sides of each stator core 10 are cooled, the coils can be efficiently cooled.

  In the present embodiment, the rotors 20, 50, 60 are permanent magnet rotors, but the present invention is not limited to this. For example, a winding field rotor including a plurality of teeth and a coil concentratedly wound on each tooth may be employed as the rotor.

  In addition, the rotary electric machines 1-3 which concern on this embodiment may be used as an electric motor, and may be used as a generator. Below, the example which utilized the rotary electric machine 1 which concerns on 1st Embodiment as a generator in a wind power generation system is shown.

  As shown in FIG. 7, the wind power generation system 70 includes a windmill 71 that rotates by receiving the force of wind, a speed increasing gear 72 that accelerates the rotation of the windmill 71 and transmits the speed to the rotating electrical machine 1, and the first The same rotating electrical machine 1 as that of the embodiment, a wind turbine nacelle 73 for housing the speed increasing gear 72 and the rotating electrical machine 1, a power converter 74 for converting the power generated by the rotating electrical machine 1 into predetermined power, and this It is mainly composed of a power system 75 connected to the power converter 74. According to this structure, when the wind turbine 71 rotates by receiving wind force, the rotational torque is transmitted to the rotating electrical machine 1 via the speed increasing gear 72, and the rotating electrical machine 1 generates power. In this power generation, even if the coil 13 shown in FIG. 1 is energized and generates heat, the coil end portion 13a (see FIG. 2) is cooled by the radial fan 22 that rotates as the windmill 71 rotates. It becomes.

  The speed increasing gear 72 is not necessarily provided between the windmill 71 and the rotating electrical machine 1, and the windmill 71 and the rotating electrical machine 1 may be directly connected. Instead of the wind turbine 71, a turbine used for hydroelectric power generation, a turbine used for thermal power generation or nuclear power generation, or an engine used for power generation in an automobile may be provided. However, it is most effective to use the rotating electrical machine 1 according to the present invention in wind power generation in which the installation location of the rotating electrical machine is severely limited.

It is a perspective view which shows the rotary electric machine which concerns on 1st Embodiment. It is a side view which shows the state which looked at the rotary electric machine from the side. It is a front view which shows the state which looked at the rotary electric machine from the front. It is a graph in which the horizontal axis represents the electrical angle and the vertical axis represents the cogging torque. It is a side view which shows the rotary electric machine which concerns on 2nd Embodiment. It is a side view which shows the rotary electric machine which concerns on 3rd Embodiment. It is a figure which shows the wind power generation system using the rotary electric machine which concerns on 1st Embodiment as a generator.

Explanation of symbols

1 to 3 Rotating electric machines 10, 40 Stator core 10A First stator 10B Second stator 11 Yoke part 12 Teeth part 13 Coil 13a Coil end part 20, 50, 60 Rotor 21 Magnet part 22 Radial fan 70 Wind power generation system 71 windmill 72 speed increasing gear 73 windmill nacelle 74 power converter 75 power system

Claims (9)

While including a plurality of stator cores in which coils are concentratedly wound on teeth portions that are formed so as to protrude inward from the annular yoke portion,
A rotating electrical machine including a rotor that is disposed so as to pass through the plurality of stator cores and that rotates with respect to the stator core by a magnetic field generated from the teeth portion,
A rotating electrical machine, wherein the rotor is provided with a fan for cooling a coil end portion of the coil. The rotating electrical machine according to claim 1, comprising two stator cores,
A rotating electrical machine, wherein one stator core is shifted from the other stator core by a predetermined phase difference. The rotating electrical machine according to claim 1, comprising three stator cores,
2. A rotating electrical machine, wherein the two outer stator cores are shifted by a predetermined phase difference with respect to the stator core disposed in the middle. The rotating electrical machine according to claim 3,
The rotating electric machine according to claim 1, wherein the thickness of the middle stator core is the sum of the thicknesses of the two stator cores disposed outside. The rotating electrical machine according to claim 1, comprising four stator iron cores,
2. A rotating electrical machine characterized in that two outer stator cores are arranged so as to be shifted by a predetermined phase difference with respect to two middle stator cores. The rotating electrical machine according to any one of claims 2 to 5,
The rotating electrical machine according to claim 1, wherein the phase difference is 30 degrees in electrical angle. It is a rotary electric machine of any one of Claims 1-5,
The rotating electric machine is a permanent magnet rotor including a permanent magnet. It is a rotary electric machine of any one of Claims 1-5,
The rotating electric machine according to claim 1, wherein the rotor is a wound field rotor including a plurality of teeth and a coil concentratedly wound on each tooth.   A wind power generation system comprising the rotating electrical machine according to any one of claims 1 to 5.

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